Simultaneous measurement of temperature and strain based on dual SPR effect in PCF

Abstract

A novel Photonic Crystal Fiber (PCF) structure with dual Surface Plasmon Resonance (SPR) was proposed to implement simultaneous measurement of temperature and strain and resolve the cross-sensitivity problem between temperature and strain. Two symmetrical holes of the PCF was coated with golden layer and one of which was infiltrated with temperature-sensitive liquid. Through theory and numerical analyses, the influences of temperature and strain on structural parameters of the PCF were discussed and calculated. Simulation results demonstrated that the temperature and strain could be simultaneously measured with sensitivities of −6.83 nm/°C and 1.30 × 10−3 nm/με, respectively, when diethylene glycol was chosen as the temperature sensitive liquid. In particular, the influence of strain variation on the temperature sensing characters was analyzed and compensated, which could further guarantee the measurement precision of temperature.